Printing error when OSError other than FileNotFoundError occurs when deleting persistent history file with history --clear command.

Author: kmvanbrunt

cmd2/cmd2.py

@@ -3993,6 +3993,9 @@ def do_history(self, args: argparse.Namespace) -> Optional[bool]:
                     os.remove(self.persistent_history_file)
                 except FileNotFoundError:
                     pass
+                except OSError as ex:
+                    self.pexcept("Error removing history file '{}': {}".format(self.persistent_history_file, ex))
+                    return
 
             if rl_type != RlType.NONE:
                 readline.clear_history()

tests/test_history.py

@@ -520,7 +520,7 @@ def test_history_run_one_command(base_app):
     out2, err2 = run_cmd(base_app, 'history -r 1')
     assert out1 == out2
 
-def test_history_clear(hist_file):
+def test_history_clear(mocker, hist_file):
     # Add commands to history
     app = cmd2.Cmd(persistent_history_file=hist_file)
     run_cmd(app, 'help')
@@ -538,6 +538,17 @@ def test_history_clear(hist_file):
     assert out == []
     assert not os.path.exists(hist_file)
 
+    # Clear the history again and make sure the FileNotFoundError from trying to delete missing history file is silent
+    run_cmd(app, 'history --clear')
+
+    # Cause os.remove to fail and make sure error gets printed
+    mock_remove = mocker.patch('os.remove')
+    mock_remove.side_effect = OSError
+
+    out, err = run_cmd(app, 'history --clear')
+    assert out == []
+    assert 'Error removing history file' in err[0]
+
 def test_history_verbose_with_other_options(base_app):
     # make sure -v shows a usage error if any other options are present
     options_to_test = ['-r', '-e', '-o file', '-t file', '-c', '-x']